FRIDAY, Nov. 8 (HealthDay News) -- If you're allergic to gummy bears or marshmallows, you may need to be careful when getting a flu shot.

Those sweet treats contain gelatin and can trigger a reaction in people with gelatin allergy. Flu shots also contain gelatin and can cause a mild to severe reaction in people with a gelatin allergy, one expert said.

"Gelatin is used in the flu shot, as well as other vaccines, as a stabilizer. Because it is found in the vaccine, those with a known allergy to gelatin can experience allergic reactions, such as hives, sneezing and difficulty breathing," allergist Dr. Stephanie Albin said in an American College of Allergy, Asthma and Immunology (ACAAI) news release.

"Because of this, precautions should be taken, such as having a board-certified allergist administer the vaccine in a person with known gelatin allergy in case a reaction occurs," Albin added.

The problem was highlighted in a case report presented Friday at the ACAAI's annual meeting. Research presented at medical meetings should be viewed as preliminary until published in a peer-reviewed journal.

Gelatin can contain proteins derived from cows, pigs or fish. It is found in a variety of foods and drugs.

"Gelatin allergy is very rare," ACAAI President Dr. Richard Weber said in the news release. "Many food intolerances can be mistaken as allergies. Those who believe they might have an allergy should be tested and diagnosed by an allergist before taking extreme avoidance measures or skipping vaccinations. The flu shot is an important vaccine and can even be lifesaving for individuals that are at an increased risk for severe side effects associated with the flu."

Many people mistakenly believe that people with an egg allergy should not get a flu shot. However, the ACAAI says that even people with a severe egg allergy can receive a flu vaccination without special precautions.